Expanding-tool



(No Model.) 2 Sheets-Sheet 2.

N. W. PRATT, BXPANDING TOOL.

No. 527,155.' l Patented Oct. 9, 1894.

- UNITED STATES .PATENT OFFICE.

NAT. W. PRATT, OF BROOKLYN, NEW YORK.

ExPANDlNc-Tool..

SPECIFICATION forming part of Letters Patent vNo. 527,155, dated October 9, 1 894.

Application led March 3, 1893.

Serial No. 464,539. (No model.)

To a/ZZ whom, it may concern..-

Be it known that I, NAT.v W. PRATT, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Expanding or Spreading Tools, of which the following is a specification.

This invention is adapted for spreading or forming raised seats surrounding hand-holes or other apertures in wrought iron headers used in sectional steam boilers, and forother purposes.

The invention is contained in a tool comprising a tapered rotating mandrel and a series of expanding or spreading rollers, which lie adjacent to the said mandrel so that their axes converge toward a common point. The bases of the Atruncated cones which the ex-` panding rollers comprise are also tapered in a reverse direction from the main taper; the said reverse taper being so inclined as to present an outer working surface parallel to the axis of the tool adapted to give a final for` mation to the work. f

Referring to the accompanying drawings: Figure l, is an elevation partly in section, of an apparatus embodying my invention; the tool being shown in a withdrawn position; Fig. 2, a similar view showing the tool advanced into the work; Fig. 3, an enlarged sectional elevation showing the mechanism in detail; the expanding rollers being represented in a preparatory position before acting; Fig. 4, a further enlarged sectional elevation, showing the expanding rollers in an advanced position at the completion of the operation; Fig. 5, ahorizontal section of Fig. 4, taken on the line Fig. 6, a horizon? tal section of Fig. 4, taken on the line y-,yg4 Fig. 7, an inverted plan View of the expander partly in section on the line z-z, Fig. 4.

A, A, represent a suitable frame for supporting the tool upon the base B, which supports the work C, in a suitable position to be operated upon.

C', in the present instance represents a wrought-iron tubular header designed for use in sectional steam boilers wherein a series of holes a, have been punched preparatory to expanding them and forming anges on the margins of the same for raised seats for the4` hand-hole plates.

b, represents one of a series `of tube holes punched in the opposite side of the header C, through which'the expanding tool may be mounted so as to allow their radial expan 'sion when the mandrel E, is advanced between them. The mandrel E, is provided with a washer e, adapted to retain the roller frame G, from dropping oif when the tool is retracted.

The axis of the expanding rollers F, converge toward a common point in the projected axis of the mandrel E. The main taper from 2, to 3, on each roller F, comprising a truncated cone, bears on the central mandrel E, rotation being frictionally transmitted. The reverse taper from the base 3, of the truncated cone to the point 4, is of such angle as to present an outer working surface at 3, 4, substantially parallel to the axis of the mandrel E. Thus when the tool is inserted, the tapered surface 2, 3, expands the' work, while the surfaceA 3, 4, finishes the same, leaving a parallel or cylindric surface.

The roller frame G, is tapered, comprisingalso a truncated cone of such dimension as to lie within the circle of the tread of the rollers F, and hollow at the center to allow free movement of the mandrel E. The frame G, is provided with a removable cap g, for the insertion or removal of the rollers F.

A washer f, is provided at the upper end of the frame G, upon which the shoulder h, of the mandrel stock I, bears vafter the expansion of rollers F, has reached its limit and it is designed to further advance the tool inv order to force the reversed tapered surface 3, 4, through the work.

The expanding tool D, may be operated b various means. That illustrated consists as follows: The mandrel stock I, is mounted in bearings J, with freedom of longitudinal and vrotative movement, and a belt pulley K, for

rotating it, is connected by means of a spline 7', in the hub of the pulley fitted to a longi tudinal groove f1., in the stock I. L, represents a rotary joint, by which the stock I, is connected to the piston rod M, of piston N, within the hydraulic cylinder O. The working pressure desired is admitted and distribnted to cylinder O, through pipes 20, 23, and valve 24; the pressure in pipe 23, being greater than that in pipe 20.

The operation of the machine is as follows: Commencing at the preparatory position shown in Fig. 1, the valve 24, is turned to the position indicated, admitting water under high pressure from pipe 23, above the piston N, at its greater area, depressing the same advancing the stock I and tool D, into the Work and setting back the water beneath the smaller area of the piston, the mandrel E, being rotated by the belt pulley K. After the tool D, has reached the position shown in Fig. 3, its expanding operation commences in the hole a, and the mandrel E, continuing its advancement causes the rollers F, to expand and advance simultaneously until the position of the tool shown in Fig. 2, is reached. When the rollers are provided with the reversed tapered surfaces 3,

4, their advancement is continued after the expanding operation on taper 2, 3, is completed; the shoulder h, of the mandrel stock 3o I, abutting on Washer f; and the tool is further advanced by the piston N, far enough to impart a cylindric surface within the aperture a, as shown in Fig. 4. The valve 24, is then reversed to the position shown in Fig. 2, cutting olf communication of pipe 23, with the upper end of the piston N, while the communication of said pressure continues beneath the piston, withdrawing the tool so as to resume the position shown in Fig. 1. The water above the piston N, is discharged through pipe 20. The same operation is repeated, acting upon the hand-holes a, in series by advancement of holder H.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is

In an expanding tool, the combination of a tapered mandrel and a series of tapered expanding rollers, each comprising two oppositely tapered truncated cones united at their bases, one of which bears with frictional contact upon the said mandrel, and the other of which presents a working surface on a line substantially parallel with the axis of the tool.

NAT. W. PRATT.

Witnesses:

J. G. WARD, CHAs. W. FORBES. 

